Christchurch Harbour Entrance Dredging
If you are coming and going through Christchurch Harbour entrance in the coming weeks you need to be aware of the recent dredging works to the large off-shore sandbar that lies at its entrance, and how it may affect navigation through the channel.
The objective of the work has been to replenish beaches depleted due to the severity of the 2013 / 2014 winter storms using sand and shingle extracted by dredger and pumped through a floating pipeline to temporary lagoons on the beach. 25,000 cubic metre was removed before being transported by large dump trucks to depleted bays.
The Harbour entrance channel can be narrower with unexpected turns so keep a good look out. Be prepared to give way to larger vessels that may be constrained by their draught or restricted in their ability to manoeuvre. Please be aware it can take a while for channels to settle down and find their natural levels after man-made intervention.
The new navigation channel in and out of The Run has been cut through the western end of the sandbar, and is buoyed with red & green markers. Mariners should make their approach from well out on a bearing of about 290 degrees – this will change with time and storms! As the water gradually shoals to around 2.5 metre at CD (chart datum), you should be able to pick up the buoyage, lying to the north-east of the harbour entrance and follow the channel in. Do not cut the corner of the ebb-tide delta, stick to the buoyage channel. Mariners will need to do their tidal calculations bearing in mind that the bar can have less than 0.5 metre at LWS (low water springs).
We spoke to Steve Woolard, Project Engineer for Christchurch Council Engineering & Parking Services on 8 July who said "The scheme was brought in under budget and Christchurch beaches have been restored to the optimum coast protection volumes and levels, and we also have the added benefit of sandier beaches. All operations were completed by 3 July and there are no obstructions to the navigation channel".
Christchurch Harbour Entrance and The Run
In the early part of the century the Mudeford sand spit extended beyond Steamer Point. During a violent storm in 1910, the spit was breached and the channel then ran out to sea opposite Sandhills. This was followed by other serious breaches in 1924 and 1935, since when the Run at Christchurch Entrance has never been the same.
The Run is a classic stretch of water, great if you understand it, but it can be daunting to novice boaters. The good news is that warnings about the Run and local hazards in various marine guide books do tend to limit the number of boating visitors to the Harbour! If you sail, paddle or powerboat in local waters you need a good understanding of tides and our powerboat training courses always include local knowledge.
John Haynes of Blue Ride is swimming 1.5 miles…